package com.zjitc.pigstudy.utils;

import cn.hutool.core.date.DateUtil;
import cn.hutool.core.util.StrUtil;
import com.auth0.jwt.JWT;
import com.auth0.jwt.algorithms.Algorithm;
import com.mysql.fabric.xmlrpc.base.Struct;
import com.zjitc.pigstudy.domain.User;
import com.zjitc.pigstudy.mapper.UserMapper;

import org.springframework.stereotype.Component;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import java.util.Date;

@Component
public class TokenUtils {

    private static UserMapper staticUserMapper;

    @Resource
    private UserMapper userMapper;

    @PostConstruct
    public void setUserService(){
        staticUserMapper = userMapper;
    }

    /**
     * 生成token
     */
    public static String getToken(String userId,String sign){
        return JWT.create().withAudience(userId)    //将user id 保存到token里面，作为载荷
                .withExpiresAt(DateUtil.offsetHour(new Date(),2))   //2小时后token过期
                .sign(Algorithm.HMAC256(sign));     //以password作为token的密钥
    }

    /**
     * 获取当前登录的用户信息
     */
    public static User getCurrentUser(){
        try{
            HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
            String token = request.getHeader("token");
            if(StrUtil.isBlank(token)){
                String userId = JWT.decode(token).getAudience().get(0);
                return staticUserMapper.selectById(Integer.parseInt(userId));
            }
        }catch (Exception e){
            return null;
        }
        return null;
    }

}
